ok ive got a mk2, with 2ltr pinto, twin dellortos and a handful of other mods, nothing ridiculous.

NOW, what's on my mind is, she started running hot lately. ive only been driving the car for about 2 weeks, and on the recent weekend it overheated twice. i noticed it lacking power, and stalling when sitting at the lights etc, so when i pulled over, and shut the motor off the overflow hose was P*SSING out!!

had to wait 10-15 minutes to fill up the cap and make it to the next destination. twice!

now heres my trouble shooting, thermostat is operational, did this with the hand on the radiator hose test (hold for 2 minutes, when you feel it get hot all of a sudden the thermostat's just opened.. right?)

bottom hose was alot cooler, cool enough for me to question the radiators blockage amount, but this is a reco'd one i paid $180 for!

so again i dismiss that. but when i sit there with it idleing for ages, and given the occasional rev, all of a sudden the cap will open and the overflow will start gushing out.

cap screwed? or is there a deeper overheating problem?

why i question the cap is because its just a cheapy $10 item from the petrol station. is it under pressured or could it have died already?

thanks guys!!

oh and i checked the headgasket, its not blowing any bubbles through the coolant (engine cold, cap off) and no coolants being chucked out the exhaust either.

Checked the raditor flow with a garden hose?

Twin carbs..could be running lean? Getting a lot of backfiring? Tried putting a std carby back on?

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Originally posted by Avon

Checked the raditor flow with a garden hose?

Twin carbs..could be running lean? Getting a lot of backfiring? Tried putting a std carby back on?

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well im hoping to solve the overheating, so i can drive again, and take it to the dyno place around the corner from my work.

i haven't touched the carbs and they motor has only just now started running hot.

and yeah i backflushed the radiator when i had the engine out (2 weeks ago) and it seemed fine as far as i could tell??

could very well be that the radiator cap is the incorrect pressure...well it sounds that why to me...sorry dont remember/know what the cap pressure should be, thought they were mostly around the 13psi mark...i could be wrong

Sorry for no help at all

Bryan

get an over flow bottle.

Any radiator cap with 13PSI will do, you could probably up it to 16psi also. Check these things

1. Is the top Rad hose under pressure when engine temp is warm and running.
yes then Cap is ok, No then cap or hose is leaking.

2. Is the top hose under pressure when engine is cold and running.
no this is normal yes you have a head gasket leak into your cooling system.

3. thermostat which you checked

4. radiator blockage some where.

5. water pump is worn.

What you will find that the T/stat is getting lazy as yes it will be opening and flowing at low rpm and idle but once you're up and driving the rev's will be higher as well as the water pump flow will be higher and the flow literally pushes the t/stat closed allowing a build up of presure so when you stop it backs up and pumps itself out of the overflow
Get yourself a new t/stat and make sure you boil it first to make sure it opens correctly

Danny

If the motor gets hot, then the Thermo won't return to its usual self. You will find it runs a few degrees hotter then it used to.

Replace that and the radiator cap at the same time (if the motor has overheated recently). Also check the temp of the thermo - my dumb knuckle mechanic decided he'd replace my 82 degree one with a 92 degree one. He did that when changing the timing belt - I didn't ask him to do it either (which is why I've started doing this myself - I was just getting lazy)